Aerial Spraying Against Medfly to End by May 9

Aerial spraying of the pesticide malathion--a controversial staple of life for many Southern Californians since last summer when a stubborn Mediterranean fruit fly infestation was first detected--will be concluded in seven weeks, state officials announced Monday.

Henry J. Voss, director of the state Department of Food and Agriculture, set a May 9 deadline for the end of spraying in sectors of Los Angeles and Orange counties already known to be infested. Newly discovered infestations will be sprayed at least once, he said.

Voss’ announcement came as a surprise. The most optimistic forecast for an end to the malathion spraying had been sometime in June.

The decision means that several hundred thousand residents in Orange County’s two spray regions, centered in Brea and Garden Grove, will now likely face fewer than the 10 to 12 applications that originally were projected.

The eight-square-mile area around Brea has been sprayed five times since November. The 36-square-mile area around Garden Grove, where anti-malathion protests have been rooted, has been hit three times. Under the timetable announced by Voss, each may face only another three or four sprayings.

“This is what we had hoped for all along,” Orange County Agricultural Commissioner James D. Harnett said of Voss’ decision.

Local malathion critics--who in recent weeks have mounted legal challenges, letter-writing campaigns and demonstrations--greeted the news with a mixture of optimism and skepticism.

“We obviously don’t want them spraying at all, but anything to get it done sooner sounds like great news; I like that,” said Mollie Haines, a Garden Grove homemaker and an organizer of the Orange County Residents Against Malathion Spraying.

In setting the May 9 deadline, state officials explained that they had decided to go against the recommendations of a panel of scientific advisers and change tactics in the Medfly campaign, and one of the scientists warned that Voss was needlessly “painting himself into a corner.”

The nighttime sorties of malathion-bearing helicopters will be replaced by the release of millions of sterile fruit flies in infested neighborhoods. These flies are expected to mate with fertile Medflies and breed the pest out of existence.

Early in the infestation, before it spread from central Los Angeles to Orange County and the San Fernando Valley, state and county officials used sterile fruit flies, but the expanding outbreak quickly consumed available supplies. A breeding facility in Hawaii is pressing to produce more of the so-called “steriles.”

About 100 million sterile flies are being bred per week at a facility in Honolulu. Voss predicts that the number will be increased to 200 million by the beginning of May as two new facilities begin operation in the next few weeks.

Until the sterile flies arrive, Voss said spraying will have to be increased from once every three weeks to once every two weeks because of the warm weather, which makes the Medfly more active.

But Natalie Bosecker, a spokeswoman for the state-run eradication program, said most areas in the current treatment zone will receive a maximum of three more sprayings.

The five members of the state Medfly Science Advisory Panel, who had recommended last week against an early halt to aerial spraying, were skeptical and voiced concern about Voss’ announcement.

Roy Cunningham, a U.S. Department of Agriculture entomologist and the chairman of the panel, said that breeding sterile Medflies is a notoriously tricky proposition and that trying to double or triple the current level of production could cause problems.

“It frequently happens,” said Cunningham, who is considered by many the nation’s top Medfly expert. “You try to up production and quality goes right down.”

Indeed, there was suspicion that the 1981-82 infestation in Northern California was exacerbated by the release of some fruit flies that were not sterile, significantly expanding the population of fertile flies.

Cunningham warned that poor-quality flies could be too weak to compete for mates with wild flies, making them worthless in the eradication effort. He added that ending the spraying program so close to completion is a needless disruption that could destroy the progress already made.

“We’re just leaving ourselves open,” he said.

Voss’ plan to phase out aerial spraying hinges on the three sterile fly breeding facilities in Hawaii. Only one of the breeding plants in Honolulu is operating. The facility has been producing about 100 million sterile flies a week, according to Nori Tanaka, one of the entomologists in charge of the program.

Tanaka said that construction of a new facility across the street is not completed but that he is confident it would be producing up to another 150 million sterile flies by May 1.

“I don’t think we’re going to have any problems,” he said. “We will deliver.”

A bigger question mark is the new U.S. Department of Agriculture facility in Waimanalo, Hawaii.

The facility is designed to produce up to 500 million fruit flies a week, although there have been problems with the building’s environmental system, which controls temperature and humidity.

Project director Glenn Hinsdale said he hopes to be shipping about 100 million sterile flies to California by May and gradually increase to 200 million by the beginning of June.

“I think we can do it,” Hinsdale said, “but breeding flies is something you can’t force.”

If all the facilities have no major problems, the state could be receiving from 200 million to 350 million flies in May.

Even with that number of flies, Cunningham was worried whether it would be enough.

The state prescribes the use of about 1 million sterile flies for every square mile infested, and the infestation zone now covers about 500 square miles, Cunningham said.

“The math doesn’t seem to work out. I don’t know what he’s doing,” Cunningham said. “I think Mr. Voss is painting himself into a corner he didn’t have to go into.”

Bosecker, however, said the state will have completed eradication of the Medfly in many sectors by May, allowing the redeployment of sterile flies to other infested neighborhoods.

Meanwhile, in Santa Ana, a U.S. Department of Agriculture official warned that if the state cannot wipe out the Medfly, the federal government might be forced to place a quarantine on all California fruit exports.

U.S. Agriculture Secretary Clayton Yeutter “is watching this situation very closely--all the agricultural leaders across the country are,” said Fred W. Meyer, the federal official in charge of monitoring the Medfly project.

Meyer’s warning came at a public hearing held in Santa Ana by state agriculture officials on a proposal to adopt the state’s emergency regulations for handling the Medfly problem. The regulations are due for adoption within the next few weeks.

It was the first time that the state has had to hold such a hearing since the start of Southern California’s Medfly spraying campaign. Under a little-known regulation, the state has to give residents the chance to offer their views at a public hearing before it can adopt such regulations. But before Monday’s hearing, no one had exercised that right.

While Meyer and two state officials defended the state’s response to the Medfly situation, nine local residents cited health and economic concerns in attacking it. The state is now obligated to respond to concerns raised by residents in a report before the adoption of formal regulations for Medfly spraying and quarantining, said hearing officer Barbara Bunn.

State Assembly candidate Jerry Yudelson of Garden Grove, a malathion critic who requested the hearing, said Monday’s proceeding offered residents their only chance to get their concerns on record and “force (the state) to explain the Medfly program to us and their handling of it.”

But Bob Taylor, another anti-malathion organizer who testified at the hearing, was less optimistic.

“I didn’t put a lot of energy into this event, because I’m afraid it’s not going to make a lot of difference,” Taylor said.